Dienogest 2 mg Daily in the Treatment of Adolescents with Clinically Suspected Endometriosis: The VISanne Study to Assess Safety in ADOlescents

STUDY OBJECTIVE: To study the safety and efficacy of dienogest 2 mg in adolescents with suspected endometriosis. DESIGN: A 52-week, open-label, single-arm study. SETTING: In 21 study centers, in 6 European countries. PARTICIPANTS: Adolescents aged 12 to younger than 18 years with clinically suspected or laparoscopically confirmed endometriosis. INTERVENTIONS: Dienogest 2 mg once daily. MAIN OUTCOME MEASURES: The primary end point was relative change in lumbar spine (L2-L4) bone mineral density (BMD) measured using dual-energy x-ray absorptiometry. A key secondary end point was change in endometriosis-associated pain assessed using a visual analogue scale. RESULTS: Of 120 patients screened, 111 comprised the full-analysis set (ie, patients who took ≥1 dose of study drug and had ≥1 post-treatment observation) and 97 (87.4%) completed the study. Mean lumbar BMD at baseline was 1.1046 (SD, 0.1550) g/cm2. At the end of dienogest treatment (EOT; defined as at 52 weeks or premature study discontinuation), mean relative change in BMD from baseline was -1.2% (SD, 2.3%; n = 103). Follow-up measurement 6 months after EOT in the subgroup with decreased BMD at EOT (n = 60) showed partial recovery in lumbar BMD (mean change from baseline: -2.3% at EOT, -0.6% 6 months after EOT). Mean endometriosis-associated pain score was 64.3 (SD, 19.1) mm at baseline and decreased to 9.0 (SD, 13.9) mm by week 48. CONCLUSION: In adolescents with suspected endometriosis, dienogest 2 mg for 52 weeks was associated with a decrease in lumbar BMD, followed by partial recovery after treatment discontinuation. Endometriosis-associated pain was substantially reduced during treatment. Because bone accretion is critical during adolescence, results of the VISanne study to assess safety in ADOlescents (VISADO) study highlights the need for tailored treatment in this population, taking into account the expected efficacy on endometriosis-associated pain and an individual's risk factors for osteoporosis.